Today's incidents were similar to the violence in Saltillo last March, when at least two groups of Gulf cartel gunmen drove through the city, provoking gun battles with rival Zetas and local and federal authorities.
According to local media and witnesses, today's shootouts began at approximately 2:00pm between rival groups of gunmen on the city's east side in the colonias Los Cerritos, Praderas and Magisterio, where one unidentified person was reportedly killed
The fighting then spread to the Los Maestros and Guanajuato areas.
Heavy fighting between Marines and a group of gunmen was reported outside of the Technologico de Saltillo campus, where students were forced to seek refuge.
By 4:00pm fighting had spread to the periférico Luis Echeverría between Venustiano Carranza and Monclova. It was here outside of a carwash where gunmen attacked members of a state police GATE (swat type) unit, killing one officer and wounding others.
Soon after federal reinforcements arrived one federal police officer was shot and killed.
By 5:00pm the fighting had spread to the area around the Torre Elite skyscraper before finally ending.
There were no reports of other casualties or arrests as of Tuesday night.
To the east of Saltillo, in the neighboring state of Nuevo Leon, five men were murdered in the Monterrey neighborhood of colonia Independencia.
The five men were suspected "narcomenudistas" (street level drug dealers).
In the first day of November, nine persons were the victims of execution style murders in the Monterrey metropolitan area.
In the state of Nuevo Leon 1,546 execution style murders have occurred in the first 10 months of 2011. If November 1st is any indication, the number of executions for all of 2011 will be higher than 2,000.